But already, the PC is given way too much info regarding who the PC really is and limiting the term of what background the PC can have if ya give him/her any form of family relation ingame. The second bit with being force into the army is, well, too forceful of the PC already, not to mention it would go in line of "epic beginning" which would kind of lose the favor in the long run and would take too long to be consider an intro.
I like the prison beginning because it doesnt tell anything about your background. Also i like the mystery of not knowing why i was in prison,
also i can pretend to myself different reasons why. Furthermore when a person gets out of jail is a good way to get into the game, not just in some random location where you would wonder
"why am i at this particular place?".
Dont know if thats good reason enough for you. Anyway i think other beginnings could probably be good as well, but i just dont think its necessary to break the tradition when its a decent one
But ya can get an intro that does not start at the prison and still able to create ya own background without the petty need of explaining why ya in the Prison cell to begin with. As for the "good way" to get into the game, its in argue that one can just get off the ship or caravan as an intro and give any explanation by the player themselves as to why they are there in the first place. The Main Quest can come out of no where in a varies of forms from quests, letters, and/or event the player does ingame.
And again, Prison Intro was
never, ever, a tradition in the Elder Scroll. If one wanted to start with a Prison Intro that badly, go to the nearest guard and punch him in the face.